The present invention relates to an image forming apparatus for printing an image by scanning a print head in the main scanning direction, an information processing apparatus which is connected to the image forming apparatus to provide print information, an image forming system, and its control method.
Conventionally, a printer which forms an image by repeating a print scan of a print head in the main scanning direction, and feeding of a print medium in the sub-scanning direction is known. In printers of this type, those which limit the scan width and those which do not limit it upon print scan of the print head are known. When the scan width is not limited upon print scan, the print head is scanned from one end to the other of the uppermost line of a print sheet in the main scanning direction to print data. Then, the sheet is fed in the sub-scanning direction, and the same process is done for the next line. This process repeats itself until the head reaches the lowermost line of the print sheet, thus printing an image on the entire medium. On the other hand, when the scan width of the print head in the main scanning direction is limited, data is checked in the printer, and the scan width is determined on the basis of the print position to be actually printed in the main scanning direction.
However, in the prior art, when the scan width of the print head in the main scanning direction is not limited, the head must also scan a non-print range, resulting in a wasteful print process time.
On the other hand, when the scan width in the main scanning direction is limited, since data is checked in the printer and the scan width in the main scanning direction is determined on the basis of the data position to be actually printed in the main scanning direction, checking data in the printer requires a long time, and the print time cannot be shortened as expected.
Especially, when the print width in the sub-scanning direction per print scan is increased using a plurality of print heads, a longer check time is required for determining the print scan width.